Isolation Of Pulmomary Mesenchymal Stem Cells And Its Contribution To Repair Of Lung Injury

Mesenchymal stem cells (MSCs) are multipotent stem cell, which can differentiate to the cells derived of mesoderm. Most of mesenchymal stem cells locate in bone marrow, however, it is found that mesenchymal stem cells exist in many other tissue/organs. We have isolated mesenchymal stem cells derived of lung by means of adherent culture. Similar to bone marrow mesenchymal stem cells, they are fibroblast-like cells, negative for hematopoietic and endothelial markers, however, express Sca-1, CD44+, CD29 and CD105. They are long-lived in culture and can be expanded rapidly in vitro. It is noticeable that stem cell markers octamer-binding transcription factor 4 (Oct-4) and Nanog are expressed continuously in culture expanded cells. They can differentiate into adipocytes, osteoblasts and alveolar epithelial cells in vitro. They are distinguished from lung epithelial stem cells and mesenchymal stem cells previously found in terms of culture condition, immunophenotype and differentiation potential.Pulmonary mesenchymal stem cells can repair the lung injury induced by bleomycin. When infused into mice that have been given bleomycin, they can engraft in lungs and protect lung from injury. Even busulfan are administrated to suppress bone marrow stem cells migration, protective effect can be observed, which are different from bone marrow mesenchymal stem cells. Pulmonary mesenchymal stem cells can differentiate into alveolar epithelial cells in vivo, demonstrate that the cells are the multipotent cells in lung that can regenerate the alveolar epithelial cells when lung are damaged.